During the exploration for and the production of hydrocarbon products, i.e., oil and gas, like sections of casing are joined together, and like sections of tubing are also joined together for insertion down hole. Such joining together is normally accomplished by means of an intermediate coupling member. Commonly, such coupling member has oppositely directed threads interior of its opposed ends. Facing ends of adjacent casing or tubing sections, being exteriorly threaded, are then engaged and made up with said coupling ends. Certain problems have consistently occurred in the field where strings of casing and tubing are assembled. These problems have included the following (1) relative slowness in make-up, (2) tendency of the threads to gaul, especially when the coupling is broken loose, and (3) cross threading occurring, especially during make-up. Attempting to overcome these problems led to Aplicant's invention.